One of my favorite recordings is of baritone Thomas Hampson singing songs by Ives, Griffes, and MacDowell. Surprisingly poignant and melodic, the Ives lieder are just filled with wonder and calm. I played this recording while my baby was in the NICU (she was a preemie) and the music regularly quieted a room full of crying. Not all of the pieces are quiet so peaceful, so I burned a CD with my favorites and play it when my now preschooler needs some down time. A nice alternative to the usual tot lullaby CDs out there. You might also check your local library for a copy–the album was recorded in 1991.
Charles Ives’s Feldeinsamkeit (In Summer Fields), song for voice & piano, S. 250 (K. 6B27) is pure bliss.